Electrical distributing system



LLIWUWULIJ G. FACCIOL'I. ELECTRICAL DISTRIBUTINGSYSTEM.

APPLICATION FILED NOV, 26. I920;

Patented Dec, 27, 1921.

Fig.3.

Inventor: Giuseppe F'a c: cioli,

His Attorney.

* UNITED STATES PATENT orrice QIUSEPIE FACCIOLI, OF PITTSFIELD,MASSACHUSETTS, ASSIGNOR T0 GENERAL ELEC- TRIC COMPANY, A CORPORATION OFNEW YORK.

ELECTRICAL DISTRIBUTING SYSTEM.

Specification of Letters Patent.

Patented. Dec. 27, 1921;

Application filed November 26, 1920. Serial No. 426,360.

To all whom it may concern:

Be it known that I, GIUsEPPn FACOIOLI, a citizen of the United. States,residing at Pittsfield, in the county of Berkshire, State of,Massachusetts, have invented certain new and useful Improvements inElectrical Distributing Systems, of which the following is aspecification.

My invention relates to electrical distributing systems, and has for itsobject an improved arrangement of parts for controlling the same. Y

More particularlymy invention relates to three-wire systems supplyingdistributing transformers, and provides improved connections therefor,by which the loads on the distributing transformers may be selected by asimple switching operation at the central station.

Where distributingtransformers on threewire systems have a variety ofloads thereon, as where there is a lighting load and a power load, itmay occur that approximately maximum values of both loads are thrown onthe system at substantially the same time. By reason of the differentnatures of the loads it is generally assumed that maximum values of thetwo loads will not occur simultaneously, but theexpe-rience of centralstation operators is that twosuch loads invariably overlap in the courseof the days run and during such overlapping period, or period of theso-called peak load, the supply system and its transformers may easilybecome overloaded.

By my invention this occurrence is made impossible for Iemploy anovelarrangement of thetransformers and connections which enables thecentral station operator or load despatcher to select at will by asimple switching operation, which load is to be supplied with power.

For a more complete understanding of the nature and objects of myinvention reference should be had to the following detailed descriptiontaken in connection with the accompanying drawing, in which Figure 1shows in diagrammatic fashion an electrical distributing system providedwith my invention; Fig. 2 shows the same system in which the centralstation switch has been shifted to cut out one of the loads; Fig.3shows-in similar fashion a system embodying a modified arrangement ofparts,

while Figs. 4:, 5 and 6 show portions of such a s stem.

eferring now to the drawin s, A and B represent the windings on thesecondary or supply side of two main transformers, here assumed to be atthe central station. The windings A and B supply the three feeders 10,11 and 12 with electricalenergyacross which are connected the primariesP and P of two distributing transformers whose secondaries S and Ssupply the loads on the system. The two primaries P and P are connectedso as to have the feeder 11 in common, the secondaries being similarlyconnectedto their loads through the distributing wires 20, 21 and 22.The loads on the secondaries are indicated as of two kinds, a power loadbeing shown at 25 and lighting loads at 26 and 26 respectively.

The power load 25 as shown in Fig. 1 is shown as a pure resistance andis connected cross the two secondaries S and S in series withoutconnection to the common return wire'21. The power load indicated at 25,however, need not be a pure resistance but may be any load presumablyhaving characteristics as to constancy, durationand time of demand whichdiffer from the characteristics of the lighting loads at 26 and 26'.Such loads may be series lighting loads, as indicated at 25 in Fig. 5.or motor loads, as are indicated at 25" in Fig. 6. t

The lighting loads 26 and 26 are individually connected across thesecondaries S and S. the load 26 being connected to wires 20 and 21 tobe across secondary S while load 26 is connected to wires 21 and 22 tobe across secondary S The switching device for cutting out at will, whatin the instance illustrated is the power load 25, comprises a reversingswitch for changing the polarity of one of the main transformers withrespect to the feeders at 10, 11 and 12. A two-throw reversing switch Kis connected across feeders 11 and 12 and has its poles 30, 31 and 32connected to the terminals of the supply winding of the main transformerB. The pole 30 1s electrically connected to pole 31 so that in oneposition of switch K pole 31 is connected to feeder 11 and pole 32 tofeeder 12 while in the other position pole 32 is connected to feeder 11and pole 30 (or its equivalent pole 31) to feeder '12. This latterposition of the switch K is shown in F ig.2, the'forrner being shown rand d as in series. In this position it is therefore seen that there isan E. M. F. to

them with current, the

supply current to each of the loads'26 and 26" and an E. M. F. ofsubst-antitlly twice the magnitude of that across the lighting loads tosupply current to the power load. 7

Should the load despatcher at the central station at sometime determinethatthe combined loads at 25, 26 and 26 exceed the desired maximum, orfor any other reason, hemay out out the power load by throwing switch Kfrom the position indicated in Fig. 1 to the position indicated in Fig.2. V

In the position shown in Fig. 2, the main transformerat B nowhasreversed polarity with respect to the feeders 11 and 12 so that thepolarity of-primary winding P is reversed, as indicatedby the arrow dwhich is reversed with respect to arrow 0. It is thus seen that in thissecond position of switch K the E. M.Fs. of the supply transformers arebucking so that while there is an E. M. F. acting across each load '26and 26' to supply resultant E. M. F. from the series connection of thetransformers across the power load is zero; hence no current will flowto the power load.

This same effect, however, may be had from a switching device other thana double throw switch.1 "A device for effecting the connections shown inFig. 3 will also pro duce buckin E. M. Fs. inthesupply transformers. nFig. 3, the connections are changed from' the series arrangement of Fig.1' to one in which the main transformers A and B arein multiple and thefeeder 12 connected to vfeeder 10. Then since the supply transformersare in multiple the lighting loads 26 and 26 willhave F. across the sameto supply current thereto but the load at 25 which is across the sec--ondaries ofthe supply transformers in series has a zero resultant E.MrF, 'thereacross. This latter arrangement has the obvious advantagethat the lighting loadsat 26 and 26 need not be balanced inorder todistribute themselves in an economical manner across the transformers Aand B, because the t two loads are in multlple which are supplied by thetransformers A and B which are themselves also in multiple'by thisconnection.

Having now described anembodiment of my invention which is "at presentthe best means known to me for jcarrying'the same into effect, 1 wouldhaveit understood that thisismerely illustrative andthat I do not meanto "be'limited thereby t the precise tr nsformeraof a plurality ofs'upplytrans: V rormers fed therefromand havinga feeder in common, aplurality of loads having different characteristics connected across thesupply transformers individually and in series re gectively, and aswitching. device for changing the polarity of a main transformer withrespect to its feeders whereby a zero resultant M. F may be had from theseries'connection of said supply transformers. V V r 2. In an electricaldistributingsy'stem, the combination with a plurality of maintransformers, of a plurality of supply transformers fed therefrom andhaving a feeder in common, a plurality of loads having differentcharacteristics connected across the s pply transformers individuallyand in series respectively, and a double-throw switch for changing thepolarity of main transformer with respect to {its feeders whereby a zeroresultant l /LF. is im: pressed across the load on the series connectionof said supply transformers, V V V 3. In an electrical distributingsystem, the

combination with two maintransformers,"

of two supply transformers fed therefrom and havi one feeder incommon,loads con-- 'nected across the supply transformers individually, anotherload having a characteristic different from the first, said loadconnected across said supply transformers in series, and a switchingdevice for'reVerS- the polarity of a main transformer with respect toits feeders whereby the E. i

M. Fs. of the supplytransformers acrossthe second named load may be 111series or bucking relation a. in an l distributing system, thecombination with t /c main transformers, of two" supply transformers fedtherefrom and having one loads connected across the supply trans ers,whereby a zeroresultant E. M. F, may i f de in commony 115 ormersindividually, another loadhav ng V be had from the series connection ofsaid I loads.

6. In an electrical distributing system, the combination with two mainsources of current, of two loads connected across the sources of currentindividually and having one feeder in common, another load connectedacross the sources of current in series,

